MazdaCX-92021Overview/mazda/cx-9/2021/base/

2021 Mazda CX-9

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2021 CX-9.

Transmission Automatic (S6)

The 2021 Mazda CX-9 is a three-row crossover utility vehicle fitted with an automatic six-speed transmission and an engine requiring 5.1 quarts of 5W-30 oil, achieving EPA fuel economy ratings of 22 mpg city, 28 mpg highway, and 24 mpg combined. Within the model’s 20072023 complaint history, the 2021 model year’s tally of 35 owner grievances positions it well below the 2012 high of 221 yet above the 2022 low of 9, with its single recall and engine-category top complaint indicating that while overall reliability has improved significantly, specific mechanical concerns still warrant attention.

Model year202320222021201220112010200920082007

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity5.1 qtOEM · verified
Engine oil type5W-30OEM · verified
Lug nut torque80.0-108.0 ft-lbsOEM · verified
EPA fuel economy22/28/24 mpgEPA · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 35 · 520 CCA battery, OE oil filter 1WPY14302. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 35 · 520 CCAOEM · verified
Tire sizeP255/50R20 104VOEM · verified
Wheel / rim8.5 inOEM · verified

OE service part numbers OEM · verified

Engine oil filter1WPY14302
Engine air filterPY8W133A0
Spark plugPY8V18110
Battery0000800035WB
Front wiper bladesTK7867330 alt TK4867330
Serpentine beltP30115908 alt PY0115909A
ThermostatP50215171
Cabin air filterTK4861J6X

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic (S6)

Dimensions & weight NHTSA vPIC

Overall length199.6 in
Overall width77.6 in
Overall height67.7 in
Wheelbase115.4 in
Curb weight4387 lb
Track (front / rear)64.6 / 64.6 in
Weight distribution (front / rear)55/45

Ratings & economy EPA / vPIC

EPA city / highway / combined22 / 28 / 24 mpg
DrivetrainFront-Wheel Drive
Recommended fuelRegular Gasoline

Performance & power Independent road tests

0–60 mph, quarter-mile, horsepower and torque from independent road tests.

Independent road tests for the CX-9 of this era, listed by trim and engine — this page spans more than one engine, so no single horsepower figure is shown.

7.2 sec0–60 mph (tested)quickest 7.20 sec — 2021 Signature
YearTrim / engine0–60¼ mileHPDrivetrain
2021Signature 2.5L Turbo I-47.20 sec15.40 sec250 hpAWD
2020Signature 2.5L Turbo I-47.00 sec15.40 sec250 hpAWD
2020Signature 2.5L Turbo I-47.10 sec15.50 sec250 hpAWD
2019Signature 2.5L Turbo I-47.30 sec15.70 sec250 hpAWD
2018Signature 2.5L Turbo I-47.00 sec15.50 sec250 hpAWD
2018Grand Touring 2.5L Turbo I-47.10 sec15.50 sec250 hpAWD
2017Signature 2.5L Turbo I-46.80 sec15.40 sec250 hpAWD
2017Touring 2.5L Turbo I-47.20 sec15.50 sec250 hpAWD

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 5.1 qt of 5W-30 engine oil, Mazda Long Life Hypoid Gear Oil SG1 in the differential, DOT 3 brake fluid. Torque lug nuts to 80.0-108.0 ft-lbs, the oil drain plug to Use a new washer: 23.0-30.0 ft-lbs. The firing order is 1-3-4-2.

Lubricants & capacities

Automatic Transmission FluidATF
Automatic Transmission Fluid Capacity8.4 qt
Brake FluidDOT 3
Differential Gear OilMazda Long Life Hypoid Gear Oil SG1
Engine CoolantMazda FL-22 Coolant
Engine Coolant Capacity10.5 qt
Engine Oil5W-30
Engine Oil Capacity5.1 qt

Engine torques

Engine Flywheel Bolts80.0-85.0 ft-lbs
Exhaust Manifold to Cylinder Head Bolts32.0-47.0 ft-lbs
Engine Oil Pan Drain PlugUse a new washer: 23.0-30.0 ft-lbs
Oil Pump to Cylinder BLock Bolts/Studs15.0-19.0 ft-lbs

Chassis torques

Differential Fill PlugFinal Drive: 30.0-39.0 ft-lbs
Lug Nuts80.0-108.0 ft-lbs
Transfer Case Fill PlugUse a new gasket: 30.0-42.0 ft-lbs
Transfer Case Drain PlugUse a new gasket: 30.0-42.0 ft-lbs

Ignition

Cylinder Firing Order1-3-4-2
Curb Idle Speed (No Load)Setting Speed: 700 rpm
Curb Idle Speed Variance (No Load)50 rpm
Curb Idle Speed (Secondary Under Load)Electrical or AC Speed-Up: 725 rpm
Curb Idle Speed Variance (Secondary Under Load)75 rpm
Spark Plug ManufacturerMazda
Spark Plug Gap0.028-0.031 in
Spark Plug Torque12.0-14.0 ft-lbs

Battery & A/C

Refrigerant CapacityR-1234yf & R-134a
Oil GroupPAG
Oil TypeR-134a: Pag 46; R-1234yf: Pag 46YF
Oil Capacity6.09 oz
Standard BCI Group Number35
Standard BCI Cranking Performance520 cca

Brakes

Brake Caliper Bolt to Carrier TorqueFront: 62.0-; Rear: 17.0-
Brake Caliper Carrier to Hub Bolt Torque88.0-95.0 ft-lbs
ABS Sensor Torque6.5
Minimum Pad Thickness0.079" in
Vented Rotor Minimum Thickness for ReplacementFront: 1.024; Rear: .354
Vented Rotor Minimum Thickness after RefinishFront: 1.055; Rear: .386
Variation from Parallelism Thickness Variation.0006"
Maximum Rotor RunoutFront: .002; Rear: .004

Multi-step torque procedures OEM · verified

Camshaft Bearing/Carrier Cap Bolts or Studs — tightening sequence 1 stages
127.0-53.0 inch lbs., Step 2: 71.0-97.0 inch lbs.27–53 in
Connecting Rod (Large End) Bearings — tightening sequence 1 stages
120.0-23.0 ft. lbs., Step 2: 80-100°20–23 ft. lbs
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
167.0-81.0 ft. lbs., Step 2: 55-65°67–81 ft. lbs
Cylinder Head — tightening sequence 1 stages
19.5-12.5 ft. lbs., Step 2: 32.0-34.0 ft. lbs., Step 3: 85-95°, Step 4: 85-95°9.5–12.5 ft. lbs

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 7,500 mi; spark plugs every 40,000 mi; coolant at 120,000 mi. The big-interval services (at 120,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

Every 7,500 miBrake Linings (inspect) · Brake Rotor (inspect) · Engine Oil (drain & refill) · Engine Oil Filter (replace) · Tire & Wheel Assembly (rotate)
Every 15,000 miBody Fasteners (torque) · Brake Line (inspect) · CV Joint Boot (inspect) · Cabin Air Filter (replace) · Fuel Line (inspect) · Steering Linkage (inspect)
Every 22,500 miAccessory Drive Belt (inspect) · Engine Air Filter Element (replace)
Every 30,000 miFuel Evaporative Emission Control System Lines (inspect)
Every 37,500 miExhaust System (Complete) (inspect) · Exhaust System Heat Shield (inspect)
Every 40,000 miSpark Plugs (replace)
At 120,000 miEngine Coolant System (drain, flush & refill)
At 180,000 miEngine Coolant System (drain, flush & refill)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

The second-generation CX-9 (2016–2023) has followed a clear maturity arc: complaints spiked at launch in 2016 (99 complaints, 577 TSBs) as the new platform settled in, then steadily declined through 2020 to a generational low of just 19 complaints and 326 TSBs. The 2021 model year breaks that downward trajectory modestly, with complaints rising to 35 and TSBs jumping back up to 420 — though both figures remain well below the early-generation peaks and far below the first-generation highs of 170–221 complaints seen in 20082012. Engine concerns dominate the 2021 complaint mix at 17 of 35 reports, and the year carries 6 crash-related complaints with zero fire complaints; the data does not specify root causes for any of these categories. By 2022–2023, complaints fall to near-trivial levels (9 and 12 respectively) with zero recalls, suggesting the 2021 uptick was a transient blip rather than the start of a systemic problem. **Bottom line:** the 2021 CX-9 is a solid buy — it's a late-cycle model with most launch issues long since engineered out, and its complaint volume is low in historical context, though buyers should pay particular attention to engine operation during pre-purchase inspection given the concentration of complaints in that category.

1
Open recalls
NHTSA campaigns
420
Service bulletins
Manufacturer communications
0
ODI investigations
Office of Defects Investigation
35
Owner complaints
6 involved a crash · 0 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Overall★★★★★
Frontal★★★★
Side★★★★★
Rollover★★★★
Owner complaints by model year NHTSA · this generation & adjacent

Owner complaints filed with NHTSA, by component

All 35 complaints on record, top 8 components.

Engine17
Unknown Or Other3
Service Brakes2
Back Over Prevention1
Power Train1
Forward Collision Avoidance1
Suspension1
Vehicle Speed Control,Engine1

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 1 of 1 campaigns on record for this vehicle.

21V750000Seats:Mid/Rear AssemblyReported 27/09/2021

Mazda North American Operations (Mazda) is recalling certain 2020-2021 CX-9 vehicles equipped with 60/40 split bench second-row seats. The left-side second-row seat may unexpectedly slide forward during a crash. As… Remedy: Dealers will replace the internal parts of the affected second-row seats, free of charge. Owner notification letters were mailed November 4, 2021. Owners may contact Mazda…

Technical service bulletins NHTSA · verified

Showing 5 of 420 bulletins on record with NHTSA.

BulletinDateComponentSummary
SA-042-262026-06-30Electrical SystemThis Service Alert supersedes the previously issued SAs listed below. The changes are…
SA-041-262026-06-18Electrical SystemThis SA supersedes the previously issued SA(s) listed below. The changes are noted in…
09-019-262026-06-17Electrical SystemThis bulletin supersedes the previously issued bulletin(s) listed below. The changes are…
SA-027-26a2026-06-16Electrical SystemThis SA supersedes the previously issued bulletin(s) listed below. The changes are noted…
SA-040-262026-06-15Electrical SystemThis Service Alert supersedes the previously issued SA(s) listed below. The changes are…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific CX-9. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Reference guides

Cross-vehicle references for the kinds of data on this page.

Frequently asked

How much oil does the 2021 CX-9 take?

5.1 qt of 5W-30, per the factory manual.

Does the 2021 CX-9 have open recalls?

NHTSA lists 1 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the CX-9 get?

EPA figures are 22 city / 28 highway / 24 combined mpg.